TELLDIR(3) Linux Programmer's Manual TELLDIR(3)
NAME
telldir - return current location in directory stream
SYNOPSIS
#include <dirent.h>
long telldir(DIR *dirp);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
telldir(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE
DESCRIPTION
The telldir() function returns the current location associated with the
directory stream dirp.
RETURN VALUE
On success, the telldir() function returns the current location in the
directory stream. On error, -1 is returned, and errno is set appropri-
ately.
ERRORS
EBADF Invalid directory stream descriptor dirp.
CONFORMING TO
4.3BSD, POSIX.1-2001.
NOTES
In glibc up to version 2.1.1, the return type of telldir() was off_t.
POSIX.1-2001 specifies long, and this is the type used since glibc
2.1.2.
In early file systems, the value returned by telldir() was a simple
file offset within a directory. Modern file systems use tree or hash
structures, rather than flat tables, to represent directories. On such
file systems, the value returned by telldir() (and used internally by
readdir(3)) is a "cookie" that is used by the implementation to derive
a position within a directory. Application programs should treat this
strictly as an opaque value, making no assumptions about its contents.
SEE ALSO
closedir(3), opendir(3), readdir(3), rewinddir(3), scandir(3),
seekdir(3)
COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
2013-03-24 TELLDIR(3)